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43
Fourdimensional String Compactifications with DBranes, Orientifolds and Fluxes
"... This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with Dbranes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct fourdimensional orientifold vacua, with the final aim to ..."
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Cited by 147 (18 self)
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This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with Dbranes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct fourdimensional orientifold vacua, with the final aim to come as close as possible to the supersymmetric Standard Model. Furthermore, we outline the available methods to derive the resulting fourdimensional effective action. Finally, we summarize recent attempts to address the
Families of strong KT structures in six dimensons
 Comment. Math. Helv
"... Abstract. This paper classifies Hermitian structures on 6dimensional nilmanifolds M = Γ\G for which the fundamental 2form is ∂∂closed, a condition that is shown to depend only on the underlying complex structure J of M. The space of such J is described when G is the complex Heisenberg group, and ..."
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Cited by 63 (14 self)
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Abstract. This paper classifies Hermitian structures on 6dimensional nilmanifolds M = Γ\G for which the fundamental 2form is ∂∂closed, a condition that is shown to depend only on the underlying complex structure J of M. The space of such J is described when G is the complex Heisenberg group, and explicit solutions are obtained from a limaçonshaped curve in the complex plane. Related theory is used to provide examples of various types of Ricciflat structures.
HETEROTIC SUPERSYMMETRY, ANOMALY CANCELLATION AND EQUATIONS OF MOTION
, 2009
"... We show that the heterotic supersymmetry (Killing spinor equations) and the anomaly cancellation imply the heterotic equations of motion up to two loops in dimensions five, six, seven, eight if and only if the connection on the tangent bundle is an instanton. For heterotic compactifications in dimen ..."
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Cited by 25 (1 self)
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We show that the heterotic supersymmetry (Killing spinor equations) and the anomaly cancellation imply the heterotic equations of motion up to two loops in dimensions five, six, seven, eight if and only if the connection on the tangent bundle is an instanton. For heterotic compactifications in dimension six this fixes an unique choice of the connection on the tangent bundle in the α′ correction of the anomaly cancellation.
CalabiYau connections with torsion on toric bundles
"... We find sufficient conditions for principal toric bundles over compact Kähler manifolds to admit CalabiYau connections with torsion, as well as conditions to admit strong Kähler connections with torsion. With the aid of a topological classification, we construct such geometry on (k −1)(S 2 ×S 4)#k( ..."
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Cited by 24 (0 self)
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We find sufficient conditions for principal toric bundles over compact Kähler manifolds to admit CalabiYau connections with torsion, as well as conditions to admit strong Kähler connections with torsion. With the aid of a topological classification, we construct such geometry on (k −1)(S 2 ×S 4)#k(S 3 ×S 3) for all k ≥ 1. 1.
Intersecting Brane Solutions in String and MTheory
 HEPTH/9803116 J.M.FIGUEROAO’FARRIL, “INTERSECTING BRANE GEOMETRIES” HEPTH/9806040 P.K.TOWNSEND, “BRANE THEORY SOLITIONS”, HEPTH/0004039
, 2008
"... We review various aspects of configurations of intersecting branes, including the conditions for preservation of supersymmetry. In particular, we discuss the projection conditions on the Killing spinors for given brane configurations and the relation to calibrations. This highlights the close connec ..."
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Cited by 18 (2 self)
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We review various aspects of configurations of intersecting branes, including the conditions for preservation of supersymmetry. In particular, we discuss the projection conditions on the Killing spinors for given brane configurations and the relation to calibrations. This highlights the close connection between intersecting branes and branes wrapping supersymmetric cycles as well as special holonomy manifolds. We also explain how these conditions can be used to find supergravity solutions without directly solving the Einstein equations. The description of intersecting branes is considered both in terms of the brane worldvolume theories and as supergravity solutions. There are wellknown simple procedures (harmonic function rules) for writing down the supergravity solutions for supersymmetric configurations of orthogonally intersecting branes. However, such solutions involve smeared or delocalised branes. We describe several methods of constructing solutions with less smearing, including some fully localised solutions. Some applications of these supergravity solutions are also considered – in particular the study of black holes and gauge theories.
On some properties of the manifolds with skewsymmetric torsion and holonomy SU(n) and Sp(n
"... Abstract In this paper we provide examples of hypercomplex manifolds which do not carry HKT structure, thus answering a question in [13]. We also prove that the existence of HKT structure is not stable under small deformations. Similarly we provide examples of compact complex manifolds with vanishin ..."
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Cited by 12 (4 self)
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Abstract In this paper we provide examples of hypercomplex manifolds which do not carry HKT structure, thus answering a question in [13]. We also prove that the existence of HKT structure is not stable under small deformations. Similarly we provide examples of compact complex manifolds with vanishing first Chern class which do not admit a Hermitian structure with restricted holonomy of its Bismut connection in SU(n), thus providing a counterexample of the conjecture in [15]. Again we prove that such property is not stable under small deformations. 1.
Constructing Balanced metrics on some families of nonKähler Calabi–Yau threefolds, arXiv:0809.4748v1 [math.DG
"... Abstract. We construct balanced metrics on the family of nonKähler CalabiYau threefolds that are obtained by smoothing after contracting (−1, −1)rational curves on Kähler CalabiYau threefold. As an application, we construct balanced metrics on complex manifolds diffeomorphic to connected sum of ..."
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Cited by 12 (2 self)
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Abstract. We construct balanced metrics on the family of nonKähler CalabiYau threefolds that are obtained by smoothing after contracting (−1, −1)rational curves on Kähler CalabiYau threefold. As an application, we construct balanced metrics on complex manifolds diffeomorphic to connected sum of k ≥ 2 copies of S 3 × S 3. 1.
Curvature of (special) almost Hermitian manifolds
, 2005
"... We study the curvature of almost Hermitian manifolds and their special analogues via intrinsic torsion and representation theory. By deriving different forumlæ for the skewsymmetric part of the ∗Ricci curvature, we find that some of these contributions are dependent on the approach used, and for ..."
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Cited by 8 (3 self)
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We study the curvature of almost Hermitian manifolds and their special analogues via intrinsic torsion and representation theory. By deriving different forumlæ for the skewsymmetric part of the ∗Ricci curvature, we find that some of these contributions are dependent on the approach used, and for the almost Hermitian case we obtain tables that differ from those of Falcitelli, Farinola & Salamon. We show how the exterior algebra may used to explain some of these variations.